1. Field of the Invention
The present invention relates to a cleaning apparatus and cleaning method for cleaning vacuum processing apparatuses used for manufacturing semiconductor devices, flat panel display boards and other products, and for cleaning test devices having vacuum processing apparatuses used for testing semiconductor devices, flat panel display boards and other products.
2. Description of the Related Art
Recently, vacuum processing apparatuses using plasma are widely used in the process of manufacturing semiconductor devices and flat panel displays. In plasma vacuum processing apparatuses, reactive gases or deposition material gases fed into a vacuum reactor are discharged via microwaves and high frequencies so as to process a sample to be processed placed on the stage. Components of the plasma vacuum processing apparatuses include metal components, components made of insulating material, and metal components having surfaces coated with insulating material.
Methods for removing particles attached to components include wiping the components by hand using fabric dampened with organic solvent, cleaning performed via ultrasonic waves, cleaning performed via cleaning sheets, cleaning performed by injecting dry ice (CO2), cleaning performed by injecting high-pressure water, and cleaning performed by injecting a mixture of gas and fluid.
Japanese patent application laid-open publication No. 2004-82038 (patent document 1) discloses a method for cleaning an object to be cleaned by injecting a cleaning medium through an ultrasonic cleaning nozzle. Further, Japanese patent application laid-open publication No. 2007-19443 (patent document 2) discloses a prior art cleaning method of placing a wafer having a conductive resin coating on a stage, applying voltage to the stage so as to hold the wafer on the stage, and removing particles on the stage.
However, if the cleaning method disclosed in patent document 1 is used to clean the insulating body coated on the surface of the metal component, the particles attached to the fine surface roughness on the surface of the insulating body coated on the surface of the metal component may not be removed since ultrasonic waves do not reach the depth of the fine surface roughness on the surface of the insulating body.
Further prior art cleaning methods include cleaning performed by injecting powdered dry ice to an object to be cleaned (refer for example to Japanese patent application laid-open publication No. 2007-117838), cleaning performed by immersing the object to be cleaned in a cleaning fluid and spraying high-pressure fluid through a nozzle to the object to be cleaned in an atomized state (refer for example to Japanese patent application laid-open No. 2000-21832), and cleaning performed by injecting a cleaning fluid formed by mixing gas and fluid onto the object to be cleaned (refer for example to Japanese patent application laid-open publication No. 2008-141049).
When applying the above-mentioned method for cleaning an object by injecting powdered dry ice, atomized fluid or cleaning fluid formed by mixing gas and fluid to clean an insulating body coated on the surface of a metal component, the particles attached to the fine surface roughness on the surface of the insulating body coated on the surface of the metal component may not be removed since the injected cleaning fluid or the like do not reach the depth of the fine surface roughness on the surface of the insulating body coated on the surface of the metal component.
Another prior art cleaning method proposes adhering a cleaning sheet on a wafer, and carrying the wafer having the cleaning sheet attached to the surface thereof onto a stage for placing the sample to be processed so as to clean the transfer arm and the upper surface of the stage (refer for example to Japanese patent application laid-open publication No. 2002-192084). However, this cleaning method can only be applied to cleaning flat components such as the transfer arm for transferring the sample or the stage on which the sample is placed, and cannot remove particles attached to the fine roughness on the surface of the insulating body coated on a metal component or on a curved surface of components constituting the plasma vacuum processing apparatus.
If plasma processing is started using components not having been cleaned sufficiently, the particles attached to the curved surface of the vacuum processing chamber or to the fine roughness on the surface of the insulating body coated on the surface of metal components may attach to the surface of the sample to be processed, causing defective semiconductor devices. Further, the particles attached to the surface of the sample to be processed increase the amount of contamination. Moreover, such fine particles increase in number as the particle diameter minimizes, and the very fine particles attached to the fine roughness on the surface of the insulating body coated on the surface of the metal components of the vacuum processing chamber become even more difficult to remove via cleaning using fluid. Further, since the coating on the surface of the insulating body is formed for example by thermally spraying insulating material, fine roughness is formed on the surface thereof, and the roughness may collapse if excessive pressure is applied thereto, leading to causing more particles.